The best thriller you’ll read this year might not come in paperback. Instead, it might be in the form of a text message conversation. Hooked, a fiction app aimed at teens that's currently at the top of Apple’s most-downloaded list (more than Snapchat and YouTube), presents stories that unfold through messages between the characters.

Co-founder Esha Gupta says the app came from a desire to harness the addictive properties of smartphones for something healthier than checking social media. At dinner one night, she and the other founders "were talking about how so many of us spend so much time texting—whether through Facebook Messenger or Snapchat or regular iMessage, etc.—and how maybe there is a way to use that addictive behavior but reinterpret it as a way to read and write stories,” Gupta tells mental_floss. In fall 2015, they launched Hooked, which they call "fiction for the Snapchat generation." It makes texting a literary endeavor.

The stories all revolve around online chats or texts, so opening the app is like peering into someone else’s iMessages. To advance the story, you just need to tap the screen, and a new message between the two characters will appear. In one thriller, for instance, a teenager is texting her mother about a mysterious noise she hears coming from their basement. In another, a therapist working for an online counseling site is chatting with her new patient.

Because of the fragmented, back-and-forth format of the chat stories, thrillers tend to work best, but the app also features stories in genres like romance, science fiction, fantasy, and mystery. Hooked works with authors and commissions custom stories for the app, but users can also submit their own. In total, there are a few thousand stories from both established authors and users, according to Gupta.

The stories aren't exactly highbrow literature, but they certainly are reaching a wide audience. The app currently has more than 10 million downloads, and in reviews, users almost universally refer to it as “addicting.”

Hooked (available for iOS, Android) is free, but there’s a limit to how much you can read at once. Subscribers can pay $2.99 a week or $7.99 a month to read an unlimited amount of stories in one sitting, but free users encounter a paywall after a certain amount of time. If you don’t want to upgrade, you'll have to wait 40 minutes for new content to appear.

“I think texting is such a natural form of reading and writing these days,” Gupta says. “People are on their phones constantly, and this is an easy way to escape into a fictional world with fictional characters when you're on-the-go or in spaces where you maybe have some downtime (i.e. sitting on the bus or waiting for coffee) but aren't necessarily going to have a book on you.”

[h/t CGTN]